Iron-chalcogenide FeSe$_{0.5}$Te$_{0.5}$ coated superconducting tapes for high field applications

TL;DR

This study demonstrates that FeSe$_{0.5}$Te$_{0.5}$ coated superconducting tapes exhibit high critical current densities under strong magnetic fields, showing promise for high-field applications at liquid helium temperatures.

Contribution

The paper introduces a new coated conductor approach for FeSe$_{0.5}$Te$_{0.5}$ superconductors, achieving high current densities and isotropic performance under high magnetic fields.

Findings

Critical current density >1×10^4 A/cm^2 at 4.2K under 25 T

Nearly isotropic critical current performance

Point defect flux pinning mechanism identified

Abstract

The high upper critical field characteristic of the recently discovered iron-based superconducting chalcogenides opens the possibility of developing a new type of non-oxide high-field superconducting wires. In this work, we utilize a buffered metal template on which we grow a textured FeSe$_{0.5}$Te$_{0.5}$ layer, an approach developed originally for high temperature superconducting coated conductors. These tapes carry high critical current densities (>1$\times10^{4}$A/cm$^{2}$) at about 4.2K under magnetic field as high as 25 T, which are nearly isotropic to the field direction. This demonstrates a very promising future for iron chalcogenides for high field applications at liquid helium temperatures. Flux pinning force analysis indicates a point defect pinning mechanism, creating prospects for a straightforward approach to conductor optimization.